1-(4-Bromo-2-thienyl)ethan-1-one → 2-Bromo-1-(4-bromo-2-thienyl)ethanone

HRID 1618974Notes

Reaction equation

HRID 1618974 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:7](=[O:9])[CH3:8])[S:5][CH:6]=1.[Br-:10].[Br-].[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC>CO.ClCCl>[Br:10][CH2:8][C:7]([C:4]1[S:5][CH:6]=[C:2]([Br:1])[CH:3]=1)=[O:9]

Participants

5

Procedure

To 1-(4-bromothiophen-2-yl)ethanone (10 g, 48.8 mmol) in methanol (98 mL) and dichloromethane (163 mL) is added tetra-n-butylammonium tribromide (28.8 g, 58.5 mmol). The reaction mixture is concentrated under reduced pressure at 50° C. to give a residue which is purified by silica gel chromatography, eluting with dichloromethane to give crude 2-bromo-1-(4-bromo-2-thienyl)ethanone. To a solution of the crude 2-bromo-1-(4-bromo-2-thienyl)ethanone in acetonitrile (200 ml) is added potassium carbonate (20.2 g, 146 mmol) and diallylamine (9.48 g, 97.5 mmol). The reaction is stirred at room temperature for 2 hours. Water is added and the solution is extracted with ethyl acetate. The organic phases are combined, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the crude title compound. ES/MS (m/e): (79Br/81Br) 300/302 (M+H).

Workup

  1. concentrationThe reaction mixture is concentrated under reduced pressure at 50° C.
  2. customto give a residue which
  3. customis purified by silica gel chromatography
  4. washeluting with dichloromethane

Sources & evidence

ORD record
ord-7e76881104b8435cbc3a87382a58953e
Source dataset
uspto-grants-2014_07
Patent number
US08772282B2

Reaction notes

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